Guwahati: Botanists have identified two new flowering plant species in Arunachal Pradesh’s Changlang district, with one named after Chief Minister Pema Khandu in recognition of his contribution to the state’s development and scientific activities.

The newly described species, Ophiorrhiza shidiensis and Ophiorrhiza pemae, were discovered in the Vijoynagar valley and documented in a research paper published in the journal Taiwania.

The study was authored by Krishna Chowlu, Renthlei Lalnunfeli and Vinay Kumar Sahani of the Botanical Survey of India’s Arunachal Pradesh Regional Centre and Madras Christian College.

The researchers said the plants were first observed during field surveys in March 2025. Specimens were collected when the team revisited the area in April 2026, followed by detailed examination and comparison with related species.

The findings add to the botanical knowledge of eastern Arunachal Pradesh, a region the researchers describe as rich in plant diversity but still underexplored.

Named after Pema Khandu

The name Ophiorrhiza pemae honours Pema Khandu, chief minister of Arunachal Pradesh. The paper states that the name recognises his contribution to the state’s developmental activities, particularly scientific activities.

The plant is a small perennial herb, growing about 25–40 centimetres tall. Its leaves have distinctive hairy stalks and wavy margins, while its tubular flowers are white at the base and light pink to purplish towards the middle and mouth.

It was found in the temperate montane forests of Vijoynagar, at elevations of around 2,100 to 2,600 metres.

The species is closely related to Ophiorrhiza himadrica, but the researchers distinguished it through a combination of differences in its leaves, flower structures, stipules and stigma.

The plant is currently known from a single location in the valley, with an estimated area of occupancy of four square kilometres. The researchers provisionally assessed it as Vulnerable under the IUCN criteria, noting that its restricted range could leave it exposed to human activity or other local threats.

Second species named after local community

The other new species, Ophiorrhiza shidiensis, was named after “Shidi”, the traditional name for Gandhigram used by the Lisu, or Yobin, community.

An erect perennial herb that can grow up to one metre tall, it has pale green leaves beneath and tubular flowers ranging from pale pink to rose-pink.

The species was recorded in damp, shaded forest habitats near streams and on slopes, at elevations of about 1,100 to 2,000 metres.

It is currently known from three locations in Vijoynagar. The researchers estimated its area of occupancy at 12 square kilometres and provisionally assessed it as Endangered, citing habitat degradation associated with shifting cultivation at the known sites.

Findings highlight unexplored plant diversity

Both plants belong to the Rubiaceae family, which includes coffee, and are members of the genus Ophiorrhiza. The researchers established their identities through morphological examination and comparisons with closely related species.

The paper highlights the importance of continued botanical surveys in eastern Arunachal Pradesh, which forms part of the Indo-Burma biodiversity hotspot. The authors said the discovery of two previously undescribed species through a relatively limited survey suggests further exploration could reveal additional plant diversity.